Chart templates and values.yaml in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to reference a value from values.yaml in a Helm template.

Kubernetes

image: {{ .Values.[1] }}

Drag options to blanks, or click blank then click option'

AcontainerPort

BreplicaCount

CimageName

DservicePort

Attempts:

3 left

💡 Hint

Common Mistakes

Using keys that refer to ports or counts instead of the image name.

Forgetting to use .Values before the key.

In Helm templates, you access values from values.yaml using .Values. Here, imageName is the correct key for the image name.

2fill in blank

medium

Complete the code to set the number of replicas from values.yaml in a Deployment template.

Kubernetes

replicas: {{ .Values.[1] }}

Drag options to blanks, or click blank then click option'

AreplicaCount

BimageName

CservicePort

DcontainerPort

Attempts:

3 left

💡 Hint

Common Mistakes

Using image-related keys instead of replica count.

Forgetting to use .Values prefix.

The number of replicas is usually set with the key replicaCount in values.yaml, accessed via .Values.replicaCount.

3fill in blank

hard

Fix the error in the template to correctly access the service port from values.yaml.

Kubernetes

port: {{ .Values.[1] }}

Drag options to blanks, or click blank then click option'

AcontainerPort

BreplicaCount

CimageName

DservicePort

Attempts:

3 left

💡 Hint

Common Mistakes

Using containerPort instead of servicePort for the service port.

Using keys unrelated to ports.

The service port is usually defined under servicePort in values.yaml. Access it with .Values.servicePort.

4fill in blank

hard

Fill both blanks to create a conditional block that checks if replicaCount is greater than 1.

Kubernetes

{{- if gt .Values.[1] [2] }}
replicas: {{ .Values.replicaCount }}
{{- end }}

Drag options to blanks, or click blank then click option'

AreplicaCount

B1

C0

DimageName

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong key for the first blank.

Using 0 or imageName instead of 1 for the second blank.

The gt function checks if replicaCount is greater than 1. This condition controls scaling behavior.

5fill in blank

hard

Fill all three blanks to define a container port using values from values.yaml.

Kubernetes

- name: app-container
  image: {{ .Values.[1] }}
  ports:
    - containerPort: {{ .Values.[2] }}
      protocol: [3]

Drag options to blanks, or click blank then click option'

AimageName

BcontainerPort

CTCP

DUDP

Attempts:

3 left

💡 Hint

Common Mistakes

Using servicePort instead of containerPort for the port.

Using UDP instead of TCP for the protocol.

Mixing keys for image and port.

The container image is set with imageName, the port with containerPort, and the protocol is usually TCP by default.

Practice

1. What is the main purpose of the values.yaml file in a Helm chart?

easy

A. To store default configuration values for templates

B. To define Kubernetes resource limits

C. To write deployment scripts

D. To list all Kubernetes nodes

Solution

1. Step 1: Understand Helm chart structure

   Helm charts use templates with placeholders to create Kubernetes manifests dynamically.

2. Step 2: Role of values.yaml

   The values.yaml file provides default values for these placeholders, allowing customization without changing templates.

3. Final Answer:

   To store default configuration values for templates -> Option A

4. Quick Check:

   values.yaml = default settings [OK]

Hint: Remember: values.yaml holds default settings for templates [OK]

Common Mistakes:

• Confusing values.yaml with deployment scripts
• Thinking it defines resource limits directly
• Assuming it lists Kubernetes nodes

2. Which of the following is the correct syntax to reference a value named replicaCount from values.yaml inside a Helm template?

easy

A. {{ .Values.replicaCount }}

B. {{ .replicaCount }}

C. {{ values.replicaCount }}

D. {{ .Config.replicaCount }}

Solution

1. Step 1: Understand Helm template syntax

   Helm templates access values using the .Values object followed by the key name.

2. Step 2: Match syntax for replicaCount

   The correct way is {{ .Values.replicaCount }} to get the value from values.yaml.

3. Final Answer:

   {{ .Values.replicaCount }} -> Option A

4. Quick Check:

   Use .Values.key to access values [OK]

Hint: Use .Values.key to get values in templates [OK]

Common Mistakes:

• Omitting the .Values prefix
• Using lowercase 'values' instead of .Values
• Confusing .Config with .Values

3. Given this snippet in values.yaml:

replicaCount: 3
image:
  repository: nginx
  tag: stable

What will be the output of this Helm template snippet?

{{ .Values.replicaCount }} replicas of {{ .Values.image.repository }}:{{ .Values.image.tag }}

medium

A. replicaCount replicas of image.repository:image.tag

B. Error: undefined values

C. 3 replicas of nginx:latest

D. 3 replicas of nginx:stable

Solution

1. Step 1: Read values.yaml keys and values

   replicaCount is 3, image.repository is 'nginx', and image.tag is 'stable'.

2. Step 2: Substitute values in template

   The template outputs: '3 replicas of nginx:stable' by replacing placeholders with values.

3. Final Answer:

   3 replicas of nginx:stable -> Option D

4. Quick Check:

   Values replaced correctly = 3 replicas of nginx:stable [OK]

Hint: Match keys exactly to get correct output [OK]

Common Mistakes:

• Using wrong tags like 'latest' instead of 'stable'
• Not accessing nested keys properly
• Expecting literal placeholders in output

4. You have this template snippet:

{{ if .Values.enableFeature }}Feature is enabled{{ else }}Feature is disabled{{ end }}

But the output always shows "Feature is disabled" even when you set enableFeature: true in values.yaml. What is the likely cause?

medium

A. The template syntax is incorrect and missing a closing tag

B. enableFeature is set as a string "true" instead of boolean true

C. The values.yaml file is not saved properly

D. Helm does not support boolean values in values.yaml

Solution

1. Step 1: Check boolean handling in values.yaml

   YAML treats unquoted true as boolean, but quoted "true" is a string, which evaluates as true in some contexts but false in Helm conditionals.

2. Step 2: Understand Helm conditional evaluation

   Helm expects boolean true, so if enableFeature is a string, the condition fails and goes to else.

3. Final Answer:

   enableFeature is set as a string "true" instead of boolean true -> Option B

4. Quick Check:

   Boolean true must be unquoted in values.yaml [OK]

Hint: Use unquoted true/false for booleans in values.yaml [OK]

Common Mistakes:

• Quoting booleans as strings
• Assuming template syntax error without checking values
• Not saving values.yaml after changes

5. You want to create a Helm chart template that sets the container port only if service.port is defined in values.yaml. Which template snippet correctly implements this conditional logic?

hard

A. {{- if .Values.service.port }}
containerPort: "{{ .Values.service.port }}"
{{- else }}
containerPort: 80
{{- end }}

B. {{- if .service.port }}
containerPort: {{ .service.port }}
{{- end }}

C. {{- if .Values.service.port }}
containerPort: {{ .Values.service.port }}
{{- end }}

D. {{- if .Values.service.port != null }}
containerPort: {{ .Values.service.port }}
{{- end }}

Solution

1. Step 1: Identify correct value reference

   Use .Values.service.port to access the port value from values.yaml.

2. Step 2: Use proper conditional syntax

   Helm templates use {{- if .Values.service.port }} to check if the value exists and is non-empty.

3. Step 3: Evaluate options

   {{- if .Values.service.port }} containerPort: {{ .Values.service.port }} {{- end }} correctly uses the conditional and outputs the port only if defined. {{- if .service.port }} containerPort: {{ .service.port }} {{- end }} misses .Values. {{- if .Values.service.port }} containerPort: "{{ .Values.service.port }}" {{- else }} containerPort: 80 {{- end }} adds an else block which is not requested. {{- if .Values.service.port != null }} containerPort: {{ .Values.service.port }} {{- end }} uses invalid syntax (!= null is not valid in Helm templates).

4. Final Answer:

   {{- if .Values.service.port }} containerPort: {{ .Values.service.port }} {{- end }} -> Option C

5. Quick Check:

   Use if .Values.key for conditionals [OK]

Hint: Check existence with if .Values.key, no need for != null [OK]

Common Mistakes:

• Omitting .Values prefix
• Using invalid comparison operators
• Adding unnecessary else blocks